A personal weblog of developmental cognitive neuroscience.

PAPER: An Argument For Proper Multiple Comparisons Correction

It has been a long road, but our multiple comparisons paper including the salmon has been published. See below for more details, including the abstract and a link to the download page of the journal. If you have any questions or comments please post them below or send me an email directly.

With the extreme dimensionality of functional neuroimaging data comes extreme risk for false positives. Across the 130,000 voxels in a typical fMRI volume the probability of at least one false positive is almost certain. Proper correction for multiple comparisons should be completed during the analysis of these datasets, but is often ignored by investigators. To highlight the danger of this practice we completed an fMRI scanning session with a post-mortem Atlantic Salmon as the subject. The salmon was shown the same social perspective-taking task that was later administered to a group of human subjects. Statistics that were uncorrected for multiple comparisons showed active voxel clusters in the salmon’s brain cavity and spinal column. Statistics controlling for the family-wise error rate (FWER) and false discovery rate (FDR) both indicated that no active voxels were present, even at relaxed statistical thresholds. We argue that relying on standard statistical thresholds (p < 0.001) and low minimum cluster sizes (k > 8) is an ineffective control for multiple comparisons. We further argue that the vast majority of fMRI studies should be utilizing proper multiple comparisons correction as standard practice when thresholding their data.

[...] questions about some overreaching by neuroscience (both in methods and assumptions about their validity) but even perfectly good neuroscience can be bad scholarship in extending its claims far beyond [...]

[...] to the fact that you really shouldn’t use that method for fMRI. You can read the whole paper here. The Atlantic Salmon who heroically volunteered for the study was no more than a prop. In fact, I [...]

[...] to the fact that you really shouldn’t use that method for fMRI. You can read the whole paper here. The Atlantic Salmon who heroically volunteered for the study was no more than a prop. In fact, I [...]